Universal Scaling near Band-Tuned Metal-Insulator Phase Transitions

Area of Science:

• Condensed Matter Physics
• Materials Science

Background:

• Metal-insulator transitions are crucial phenomena in condensed matter.
• Understanding the behavior of resistivity near these transitions is key.
• Existing theories struggle to explain certain experimental observations like negative dR/dT.

Purpose of the Study:

• To present a theoretical framework for band-tuned metal-insulator transitions.
• To explain the scaling of resistivity curves and the "fake insulator" regime.
• To reconcile Mooij correlations in high-temperature metals with theoretical predictions.

Main Methods:

• Utilizing the Kubo formalism for theoretical analysis.
• Investigating scaling behaviors in resistivity under specific conditions (Tτ>1 or μτ>1).
• Analyzing the power-law divergence of resistivity at critical chemical potential.

Main Results:

• The theory predicts resistivity scaling in a specific regime.
• A power-law divergence of resistivity (R_{c}∼1/T) at the critical chemical potential.
• Identification of a "fake insulator" regime with negative dR/dT on the metallic side, explaining experimental findings.

Conclusions:

• The proposed theory successfully explains scaling and the "fake insulator" phenomenon.
• This framework quantitatively accounts for Mooij correlations in high-temperature metals.
• The theory provides a unified understanding of metal-insulator transitions across diverse experimental systems.